A number of medical devices may be attached to the respiratory system of a patient while they are intubated with, for example, an endotracheal tube. Desirably, these devices may be attached, used for a period of time and detached for use elsewhere or for disposal. Various types of detachable fittings or connectors are currently in use, however, known fittings have a higher potential for failure than is desired due to manipulation by the user or caregiver.
A luer taper is used in a standardized system of small-scale fluid fittings used for making leak-free connections between a male-taper fitting and its mating female part on medical and laboratory instruments, including syringe tips, needles stopcocks and tubing. Luer taper fittings commonly have a 6 percent taper and may be tested according to (International Organization for Standardization) ISO 594-2. There are two common varieties of luer taper connections; Luer Lok® and Lure-Slip® fittings. Lure-Lok® fittings use a luer taper and are securely joined by means of a tabbed hub on the female fitting which engages threads in a sleeve on the male taper fitting. Luer-Slip® fittings conform to luer taper dimensions and are simply held together by friction. These luer fittings do not hold as well as would be desired and sometimes may be dislodged relatively easily and inadvertently by the patient or healthcare provider, resulting in the loss of ventilating system pressure and potential exposure of healthcare providers to communicable diseases of the patient. Luer fittings may also use standard threaded connections that entail screwing together two parts a number of turns to hold them securely but these fittings requires greater effort to connect and are not considered “quick connect” fittings.
Bayonet fittings are also well known and accepted in the medical field. Unfortunately, these fittings may be overridden in certain applications, like respiratory applications, resulting in a broken fitting and loss of ventilating system pressure.
Removing secretions from the tracheo-bronchial tree is an integral part of the care given to patients who are intubated and receiving mechanical or other artificial ventilation, for example. Secretions can be excessive in some respiratory disorders and constitute a serious threat to the patient having such respiratory disorders. The presence of an endotracheal tube and the associated sedation is a hindrance to the patient's efforts to clear secretions through natural coughing. In current medical practice, suction catheters are inserted through the endotracheal or tracheal tube into the trachea and main bronchus to clear such secretions from the patient's airway by suctioning.
Suctioning may be performed using an “open” or “closed” system. In the open system, the suction catheter is merely a flexible plastic tube that is inserted into the tracheal tube ventilating lumen with a source of suction connected to the proximal end of the suction catheter. The suction catheter is advanced as far as desired and suction is applied to remove secretions. Anything that the suction catheter touches before entering the lumen must be maintained in a sterile condition so a “sterile field” must be created on or next to the patient. The suction catheter must be carefully handled after it is used since it will be coated with the patient's secretions. In contrast, in the “closed” system, for example that disclosed in commonly owned U.S. Pat. No. 4,569,344, a device 10 which may be used to suction secretions uses a suction catheter 12 enclosed within a generally cylindrical plastic bag 14 to eliminate or minimize contamination of the suction catheter prior to use (FIG. 1). This is generally referred to as a “closed suction catheter” and is available under the trade name TRACH CARE® from BALLARD® Medical Products (Kimberly-Clark Corporation). As the patient requires artificial removal of secretions, the suction catheter 12 may be advanced through one end of the plastic bag 14, through a connecting fitting 1 6, into the tracheal tube and, if desired, into one of the main bronchi of the patient. The other, proximal end 17 of the suction catheter 12 is attached to a source of suction 19. Suction is applied to the proximal end 17 of the suction catheter 12 using a finger controlled valve 18 to remove the secretions. The other bronchus may likewise be aspirated. Secretions are thus drawn into the lumen of the suction catheter 12 and removed and the system remains closed. The suction catheter 12 is subsequently withdrawn from the tracheal tube and back into the plastic bag 14 to keep the circuit closed. Closed suction systems are generally preferred by healthcare providers since the provider is better protected from the patient's secretions. Closed suction systems are also easier and quicker to use since a sterile field need not be created each time the patient must be suctioned, as is required in open suction systems.
In order to change most current closed suction catheters, the patient must be disconnected from the system for a period of time while the ventilator is disconnected from the closed suction catheter that is to be replaced and connected to the new closed suction catheter. The new closed suction catheter is then connected to the endotracheal tube and ventilating of the patient is begun again. This procedure is obviously undesirable as it results in the patient being without mechanical breathing assistance for a period and it exposes the healthcare provider to the potentially communicable illnesses of the patient. Some closed suction catheter systems use detachable fittings like bayonet fittings, though, as mentioned above, these may have a higher potential for failure than is desired.
It would be desirable to have a fitting that is reliable and quick and easy to use. It would also be desirable to have a closed suction catheter that could be quickly and easily replaced without disconnecting the patient from the ventilating system.